ARTIFICIAL PROPAGATION OF TROUT. 



15 



Table 1.- 



-Velocity in feet per second and supply in r/allons per minute, long 

 cylindrical pipes flowing full — Continued. 



In using: these tables divide the head of water by the length of pipe. 

 Example : Required the flow of water in a 5-inch pipe 200 feet long 

 under a 10-foot head. 10-^-200=. 05. lief erring to the table, under 

 5/100, it is seen that under these conditions a 5-inch pipe affords a 

 velocity of 8.2 feet per second and supplies 418.02 gallons per minute. 



A square conduit conveys approximately 25 per cent more water 

 than a cylindrical pipe of the same diameter under similar condi- 

 tions. Excepting in very unusual circumstances, a pipe less than 

 3 inches in diameter should not be used. Avoid sharp bends and 

 the use of fittings as far as possible in laying the pipe line, as they 

 tend by friction to reduce the flow of water. Forty-five-degree 

 fittings are better than 90° fittings, but bending the pipe is most 

 satisfactory. Pipes up to 6 inches in diameter and sometimes 

 larger usually can be bent after heating. Abrupt bends in large 

 pipe will require flanged joints. 



If the water completely fills the conduit, air will be shut out 

 entirely, while if the conduit is larger the quality of the water may 

 be improved by aeration before it reaches the hatchery. If wood 

 61976°— 23 2 



